What subordinating conjunctions does the generator use?

The generator uses a full range of subordinating conjunctions including because, although, even though, when, while, before, after, since, until, if, unless, provided that, so that and as. The conjunction varies across generations to create structural variety.

Can I use this for NLP testing?

Yes. The complex sentence generator produces grammatically correct English sentences suitable for tokenizer testing, dependency parsing evaluation and syntax-varied test corpora. Export as JSON for direct pipeline input.

Complex Sentence Generator

Q: What is a complex sentence?

A complex sentence contains one independent clause and one or more dependent clauses introduced by a subordinating conjunction such as because, although, when, if, since, while or unless. Example: 'Although the exam was difficult, the student completed every question.'

Generate grammatically correct complex sentences with dependent clauses — for advanced ESL practice, academic writing and structured NLP test data.

⚡ Instant generation🔒 Runs in your browser🎛️ Subordinating conjunction variety📤 Export TXT / CSV / JSON / Markdown🔗 Shareable link

Complex sentence tool

Generate clause-rich sentence batches

This route fixes sentence type to Complex, then leaves the rest of the generator open so you can vary register, vocabulary and tense while staying inside dependent-clause structure.

Complex sentence generator

Generate complex sentence batches

Random category, complex structure, formal style, advanced vocabulary, long length, any tense and a five-sentence batch are preselected for this route.

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LockedComplex

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Force target nouns, verbs and adjectives into each generated sentence. Useful for writing drills, vocabulary practice and ESL teaching.

Inject a target academic word or NLP keyword to force it into every generated sentence.

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🎯 Daily challenge

Same sentence worldwide, new rewrite every day

Today's UTC-seeded challenge sentence updates once per day. Rewrite it, expand it or flip the perspective, then store your response locally and share a draft to social.

Challenge key: 2026-04-28

Today's sentence

"Each day, the reflective curator shaped a practical framework after careful review."

Rewrite the sentence with different wording while keeping the meaning.

Your response is stored locally for today's challenge.

About complex sentences

What is a complex sentence?

A complex sentence contains one independent clause and one or more dependent clauses. The dependent clause is introduced by a subordinating conjunction and cannot stand alone as a sentence.

Structure

Pattern A — Dependent clause first:
[Subordinating conjunction] + [Dependent clause],
[Independent clause]

"Although the exam was difficult,
 the student completed every question."

Pattern B — Independent clause first:
[Independent clause] +
[Subordinating conjunction] + [Dependent clause]

"The student completed every question
 although the exam was difficult."

The comma rule

Dependent clause FIRST  →  comma after dependent clause
"Although it was late, she continued working."  ✅

Independent clause FIRST  →  no comma needed
"She continued working although it was late."   ✅

What complex sentences express

Subordinating conjunction	Logical relationship	Example
because, since, as	Cause / reason	She passed because she prepared.
although, even though, while	Contrast / concession	Although it was hard, she finished.
if, unless, provided that	Condition	She will pass if she studies.
when, before, after, until	Time	Before the exam, she reviewed her notes.
so that, in order that	Purpose	She studied so that she would pass.